JEC COMPOSITES MAGAZINE - Issue #117 - November/December 2017 - 27

Fibre Patch Placement: expanding the scope of additive manufacturing

Dieffenbacher (Fiberforge) offer systems
that manufacture components with good
mechanical properties at very high speed
(tailored near-net-shape preforms are
produced in just 90 seconds or even less,
according to the latest announcements).
The good mechanical properties result
from appropriately deposited load-bearing fibres, a high fibre volume content
and good cross-linking of the thermoset
matrix. To obtain the final component
geometry, the flat "tailored blanks" are
usually formed in a thermopress. This
is an additional process step, increasing
equipment investment and extending
cycle times.
The new filament 3D printer from
Markforged, on the other hand, integrally
produces the most complex geometries
but has a very low material throughput.
Thus, additional forming steps are eliminated. Moreover, the components are
characterized by an extremely filigree fibre
architecture with complex struts and supporting structures, previously unknown.
Nevertheless, these advantages come
along with the currently very low productivity, where a part can take up to 24 hours
to be finished. Further detriments include
high material costs, low fibre volume
contents and still insufficient polymeric
connection of adjacent filaments.

however, Fibre Patch Placement components offer all the advantages of classical
CFRP components.
A key element in the automated processing
of fibre patches is the form-adaptive patch
gripper. After a two-step visual inspection,
the patches are precisely positioned on the
mould. Fibre-throughput rates suitable for
industry applications are achieved by a
high deposition frequency of 1 Hz and geometry-adjusted patch sizes. Another important aspect is the product development
process from CAD design to machine
data. Standard software for AFP processes
usually offers the user the possibility to
cover surfaces with parallel, straight tape
lines. In contrast, the Artist Studio patch
placement software, similar to modern 3D
printing software, supports the engineer
with intelligent algorithms to produce a
high-performance laminate along curved
load paths in simple steps, with no expert
knowledge of fibre layups necessary. The
algorithms move and optimize the position of the patches to obtain the maximum
laminate strength. No draping simulation
is necessary as the fibres are directly
placed 3-dimensionally. And similar to
the "print" button, the patch laminate
is automatically transferred to machine
data within the same software suite.

This simplifies the product development
process and ensures 100% compatibility
of the design with the production process.
The engineer is ideally supported in his
development work.

Light version
The patch technology, in contrast to other
technologies, can also be scaled in several
dimensions: size, material, throughput.
Production cells for high-volume production can process 15 kg/h of fibre material
and can be combined with production
lines capable of more than 100 kg/h,
processing both glass and carbon fibres
as a single component. Cevotec, the Fibre
Patch Placement specialist from Munich,
Germany, also announced a Light version
of the production system for R&D labs,
development departments and low-volume batch production. With this step,
the company encourages more engineers
to develop with and benefit from patchbased composites production. Given the
combined advantages of additive manufacturing and high-performance composites, Fibre Patch Placement is one of the
preferred options for additive composites
manufacturing currently in the market.
More information:
www.cevotec.com

Fibre Patch Placement
Combining the best of both worlds, Fibre
Patch Placement positions itself between
these two extremes. With a high degree of
geometrical flexibility, a scrap rate as low as
0%, and a simple (digital) process design,
the patch technology features major advantages of additive manufacturing. Placing
fibre patches one by one on a 3D preforming
tool, both the wall thickness and the fibre
orientation can be locally adapted to the
loads, which results in excellent mechanical
properties. Similar to 3D printing, the fibre
orientation can follow curved load paths
and thus offers more flexibly than AFP
processes. A forming step is not necessary
as the patches are deposited directly on the
final 3D contour. This means no additional
investment in a forming station and moulds.
Focusing on product performance aspects,

Fig. 2: Pressure cap being patched in the Samba Fibre Patch Placement system

N°117 November - December 2017

/ jec composites magazine

http://www.cevotec.com

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #117 - November/December 2017